What’s Wrong With the Rote Application of Lean Tools?

There is more to playing the piano than practicing scales, but you can’t get there unless you do practice scales. Likewise, there is more to Lean than tools, but you need the tools. They are not sufficient, but they are necessary. Unless you learn them, you are depriving yourself of the benefits of clever tricks, methods, and analytical tools developed over 65 years. Each one doesn’t necessarily take long to learn, but would to reinvent, and you don’t have that time.

Rote application of tools

When discussing rote application, you need to distinguish between learning by rote and applying by rote. I learned calculus by studying the theory, working out textbook exercises, and then I applied it. On the other hand, I learned to make Beef Bourguignon by following a recipe step by step, without having any understanding of why, for example, I should brown the meat before braising it. You learn different skills in different ways. Rote enables you to make an acceptable Beef Bourguignon, if not a great one, but it doesn’t work for calculus.

Whether you can or should unthinkingly apply a skill learned by rote to a real situation is another question. Once, a former plant manager who attended by Lean Logistics course told me “I have used all the tools in your course but no one had ever told me the logic behind them and the way they worked together. I was given instructions from corporate, and had to follow them or else I would have been fired, even if my plant made money.”

His former employer was an auto parts maker and, while, on the face of it, the approach seems Darth-Vader bad, it had worked for that company. Lean came from the automotive industry, so, if there is one place where brute force imitation could work, it was in auto parts manufacturing. Even though it worked in this case, the approach has two fundamental limitations:

1. Within the company itself, blindly following corporate directives does not set the stage for continuous improvement. For continuous improvement to happen, employees at all levels must have some understanding of underlying principles, and the freedom to deploy these principles in solutions they create.
2. It does not carry over to other industries. In aerospace or frozen foods, the rote application of automotive tools does not work. The pace of work, its complexity, and the business issues are different.

One area where case-by-case thinking cannot be avoided is strategy. Rote application of Lean tools is an implementation strategy that should not be rejected out of hand, because there are cases where it works. It just should not be applied in the more common situation where it doesn’t.

Tools, methods, and methodologies

Tools are devices we make or buy that enable us to do tasks we couldn’t do with our bare hands. To become adept at using a tool, we need to learn or create methods. When tools and methods are arranged in a fixed sequence to obtain a standard outcome, the result is a process or a methodology.

What are the Lean tools anyway? Wrenches, hammers, screwdrivers, power drills, or even text editors are tools. Tools are all the devices we would miss if stranded on a desert island. On the other hand, we don’t usually refer to the assembly instructions for a bookcase as a tool. Instead, we call it a method. Without the instructions, we could still figure it out, but it would take longer and involve more errors.

Tools are things we buy or build, whose possession does not make us adept at using them. Methods, on the other hand, are things we learn. The difference is clear in daily daily life but blurred in management-speak, where, for example, a method like SWOT analysis is often called a tool, event though all it has that resembles a tool is a 2×2 matrix on a white board with squares labeled “Strengths,” “Weaknesses,” “Opportunities,” and “Threats.” The value of a SWOT analysis depends exclusively on the skill of filling out this matrix in a brainstorming session.

By contrast, a piece of software that generates orbit charts, for example, is much more similar to what we call a tool, because it draws instantly and accurately a chart that would take a person hours to generate manually, with errors. In Manufacturing, we also often conflate tools and methods as, for example, in Kaoru Ishikawa’s “7 Tools of QC,” which range from checksheets to Shewhart control charts.

We like to call things tools, because, until recently, we thought we were the only species on this planet to have this concept. A few years ago, ornithologists observed a crow grabbing a stick to coax a treat out of a narrow glass tube, debunking our perception of tools as uniquely human. In the following video, you see a crow using a short tool to retrieve a longer one in order to eventually retrieve a treat:

We all have a set of tools and methods that we choose to use when the need arises. This choice is problem-solving strategy and requires thinking. You have more than just a hammer, not every problem is a nail, and you may have more than one tool you can use. A methodology is quite different, a “12-step, proven process” that you surrender to and relieves you from the need to think.

Processes, of course, are the foundation of repetitive production, and methodologies are successful for some endeavors, such as helping an alcoholic get sober, but one-size-fits-all “Lean methodologies” don’t work because the Lean transformation of any factory is more like exploring uncharted territory than building a house. There is a proven process to build a house, at least if it is a tract house without special features. When you are exploring uncharted territory, on the other hand, you don’t know what lies beyond the next hill, and must constantly adapt what you are doing to what you currently know.

The Tools of Lean

There is no consensus on what the tools of Lean are. When you google tools of Lean, you get lists from 5 to 40 items from many sources, some of which do not pertain to Manufacturing. In English, John Bicheno has two toolbox books, one for production and one for service. In French, Radu Demetrescoux’s Lean toolbox, La Boite à Outils du Lean, holds 67 tools. The best and richest source by far, however, is the Japanese literature, with numerous compilations of tools and tricks published by Nikkankogyo, and monthly installments in manga form in their Factory Management magazine (Kojo Kanri). The sources include not only Toyota but also many other Japanese manufacturing organizations.

In addition, the lists contain entries that truly do not belong together, like Jorge Luis Borges’s classification of animals. They contain small building blocks along with the systems they are part of, and items that are not tools at all. Here is an excerpt from one of the lists available on line, which reads more like a list of keywords than tools:

• 5S
• Andon
• Continuous Flow
• Gemba
• Kaizen

The “tools of Lean” in most online discussions of the subject are limited to a short list, typically including Value Stream Mapping (VSM) and 5S that play a minor role in the Toyota Productions System (TPS) and Kaizen events, Design for Six Sigma, and Activity-Based Costing that are alien to it. Unsurprisingly, the deployment of these tools fails to yield the kind of performance that generated worldwide interest in TPS.

Conventional wisdom about tools

The conventional wisdom of the Lean community today is to downplay the “tools” and emphasize management and culture instead. In this view, if top management understands the philosophy of Lean, it can make it cascade down the organization and the tools are not essential; the tools of TPS are just for the auto industry anyway, the employees are the experts, and all they need is to be unleashed in order to achieve world class performance. In other words, there is no need to study the specific tricks developed at Toyota for the past 65 years and the underlying principles are all we need.

The notion is welcome to many managers and consultants, particularly when they don’t have an engineering background, because it takes years of learning off the table. Unfortunately, this shortcut cannot be taken, and the belief that it can be is a fallacy, for the following reasons:

1. You cannot teach top management the philosophy of Lean.
2. There is more to world class performance than existing employee skills and knowledge.
3. There is no consensus on what the underlying principles are, any more than on a list of tools.
4. The underlying principles are embedded in the tools.

The following sections elaborate on these points.

Teaching management the philosophy of Lean

You can lecture managers but the best ones will not believe you. There has historically been no shortage of gurus peddling management philosophies that they claimed would make the company better, so why should they take your words more seriously? The only way their thinking can be changed is by experiencing some implementation success. The best you can do is get them to suspend disbelief long enough for carefully selected pilot projects on the shop floor to show the power of the approach. But the pilot projects invariably require the application of one or more of the tools of Lean.

Employee skills and knowledge: necessary but not sufficient

Production operators have expertise about the work they do and, often, ideas on how to improve their own workstations. At the outset of Lean implementation, however, this expertise does not extend to the design of production lines, the art of reducing setup times, or mistake-proofing, and these techniques are faster learned than reinvented.

Not all the tools developed at Toyota for making cars are applicable to, say, frozen lasagna or airplanes, and useful tools have been developed at other companies too, like Nissan’s QRQC or Lucas Industries’ Runner-Repeater-Stranger analysis. So you have to select relevant tools,  and adapt them as needed. And you may have to invent new ones.

No consensus on underlying principles

1. Focus on people are the main driver of performance.
2. Look for profits in the details of shop floor operations.
3. All manufacturing is repetitive at some level, even where it doesn’t appear to be.
4. Make materials, information, and people flow.
5. Make it easy to do what you do often.
6. Improve, don’t optimize. Optimization comes to a full stop; improvements never end.

Principles embedded in tools

While many of the “tools of Lean” would be better described as methods or tricks that have emerged as point solutions to problems Toyota encountered over the decades, and coalesced into a system, as described by Takahiro Fujimoto. For this to happen, these tools have to be the expression of common underlying principles, which no one to date has successfully and completely articulated. As a consequence, learning the tools is, in effect, the only way to grok the principles embedded in them.

“Make it easy to do what you do often” is one of the principles I have encountered in multiple tools. It is what you do when you locate the most frequently used tools and materials closest to the operator in a manual assembly station, and it becomes more elaborate when automation is involved, for example when boxing multiple electronic products, when you use a robot with suction cups to pick the relevant manuals, warranty cards and promotional coupons in a row of bins and drop them in the product box. Then, obviously, given the hardware configuration, you minimize the robot travel time by locating the bins with the most frequently used documents closest to the boxing station, but you can take it further by changing the hardware configuration, split the row of bins in two and place the halves around the boxing station, which further cuts the robot travel time in half, as shown below.

The same principle is at work in the first “S” of 5S, about decluttering the shop floor by removing all items that are not routinely used, because the effect is to make the ones that are routinely used easier to access.